Few Chrome users would be affected by the decision right now, according to Google, but the conflict over HTML5 video formats could lead to a long standards battle. Microsoft introduced two stopgap measures Wednesday for users of both Google's Chrome and the IE9 beta.

For Chrome users, at least those who also use Windows 7, Microsoft has released the Windows Media Player HTML5 Extension for Chrome, which is similar to an existing plug-in for Firefox and will allow Chrome users to play H.264 video.

"We believe that Windows customers should be able to play mainstream HTML5 video and, as we've described in previous posts, Internet Explorer 9 will support playback of H.264 video as well as VP8 video when the user has installed a VP8 codec," Microsoft interoperability program manager Claudio Caldato wrote in a blog post.

VP8 is a video technology used as part of WebM.

Microsoft's Dean Hachamovitch, corporate vice president of Internet Explorer, also released a lengthy blog post in which he criticized Google's control over the WebM project and said IE9 will support both H.264 and WebM.

"We will provide support for IE9 users who install third-party WebM video support on Windows and they will be able to play WebM video in IE9," Hachamovitch wrote.

Hachamovitch also said Google needs to "demonstrate their genuine commitment to the open standards process" and asked "will Google drop H.264 support from Android?"

"What are Google's plans for turning WebM into a genuinely open standard, one that is based on consensus like the rest of W3C's HTML5 effort?" he also wrote. "Would Google fully support such an effort? Even the WebM project's domain is controlled by Google."

Google has argued that WebM will be a more open standard than H.264 and that licensing fees will lead to H.264's downfall. "To use and distribute H.264, browser and OS vendors, hardware manufacturers, and publishers who charge for content must pay significant royalties — with no guarantee the fees won't increase in the future," Google product manager Mike Jazayeri recently wrote in defending Google's decision to drop H.264 in Chrome.

Microsoft's attack on Google Wednesday comes just one day after Google accused Microsoft of copying its search results in Bing. Microsoft is also struggling to thwart the momentum of Chrome. Despite excitement around the IE9 beta, Chrome surpassed the 10 percent usage mark in January for the first time, as Internet Explorer's market share continued to shrink from 57 percent to 56 percent of global browser usage.